Method of making and finishinga wood panel



April 30, 1935. c. E. ROZEMA METHOD OF MAKING AND FINISHING A WOOD PANEL Filed July 24, 1933 WII/mm llllllllllmm '3 iunrnon OF AND memes woon PANEL" Charles E. Grand-Rapids, Mlchu asslgnor, by mesne, assignments, to Recqnstrucg fienFinanceCorppration, a; Federal corpora H x on a H j 1 Application July Mr1933, Serial No. 681,898

scams, (01. 09)

The present invention has ,for its objectto to carry out my process; If the gluing is" done'with blood albumen glue, the temperature may not be high enough, and it maybe make one or both faces of a plywood wwater resisting and capable ofwithstanding attacks of I necessary to raise the temperature of the panels other agencies throughwhichwoodis frequently damaged and, at the same time, give to thewood in the'press beyond that required for the set- 5 a fine surface finish without having to resort [tingof the glue. 4 to. the usual sanding operation or other-similar 'Therefore', viewed in one of its aspects, the expedient's now commonly employed to' produce present invention may be said to have for its a smooth surface; f I t V "objecta simple and novelmethod'of producing 10 .Viewed in one of its aspects the present inplywood and giving it a finished surface requir- 10 ventionmay be regard'edlas having for its'object ingnosanding, and being superficially impreglto treat wood in a simple and novel mannerso nated [with an inert weather-resisting synthetic that it is protected asfullyjasthough it had "resinthat may be colored in whole or in part. thereon several coats of good paint without the 1 The'yarious features of novelty whereby my presence, however, of any superficial coating invention is characterized will hereinafter be whichfmay be scraped off in the manner of pointed'ou't'withparticularityinthe claims; but, paint; {j "forafullundstanding of my invention and of v.ln carrying out my inventioni l impregnate Hits objects and advantages, reference may be the: Wood surface" with afusible'synthetic resin, ili'ad to the following detailed description taken inpreierably of,thethermosettingtyp'el l H connection with the accompanying drawing,

complish by nbringing the panelfintoga su able wherein f r Y condition as to temperaturefand moisture cqnre 1 illustrates the gluing up "of amultiple- {tent depositingflthe resin uponqla. face; f j, ply panel between hot plates or cauls; Fig; 2 is a 'an'd Itl'ien applying a smoothing p,ressure,"preffplanviewof a fragment of the glued-panel, show- Ierablylbjrunninga roller'ioverpthe resin ing ntlieticresin overlyin'g afa'ce'of the panel, meet: 'the'panel. The heat 1 'th e layer ofiresin' being broken away at one j co er, -1 =ig'. ;3 isa section-',{on an enlarged scale, hjafragment ofthe'panel; illustrating the va of the resin-coated" face; and Fig. 4 ish a view of thefpanelsiniilar to thatshown inFig. 3, at t d of the 'rolling-operation. v rng "tofthe drawing} i represents afplycod anel gor board which," in Fig. 1,} is being glue hot press'betweeif-hotplatesor platens K 7 At the erid of thegluing' operation the in li'ible ol0rs-are mined witl'nathe o 'the wboii; theylbecome inec'au'senzofriaa fesmrcoatingo orderthem thersurface mpregnation, plywood panama accomplishedsafi firi mow .Zcost itsmustbeticarr fid figh --itheisopfiraliiongflfit mm th i process. In gluing up p ng haeiql sl minuted synit raeef tnapanew The heat, of the panelmelts the resin which flows into the dry wood. Pressure preferably is aphigh temperature 55 tent that synthetic resins can be found with tthis hot, 50

, wood into the interior for a few thousandths of an inch, depending upon various factors such as the temperature of the panel, the quantity of resin, the temperature at which the resin melts, the kind of wood, and the pressure of the roller. For example, some films that I have measured have had a thickness no greater than five onethousandths of an inch while others have had a thickness of twenty one-thousandths of an inch. In Figs. 3 and 4, which illustrate fragments of a panel on a greatly magnified scale, the dotted or stippled areas or zones 3 represent the zones permeated by the resin.

The resin may be colored, or the resin applied .to certain areas of a panel may be colored and that over remaining areas of the face of the panel be left uncolored. Furthermore, where coloring is used, there may be a plurality of different colors. For example, the resin may be so colored and be laid down in such a manner as to produce stripes; there being shown in Fig. 2 a stripe 4 of one color and a stripe 5 of another color. Where the resin is to be uniformly distributed, the color may be applied to the panel first, if desired; insoluble colors being applied dry or suspended in a liquid medium to permit them to be applied by brushing, spraying or dipping. When the resin itself is colored, the coloring matter does not pass down into the wood to the same depth as does the resin, but does enter the wood to a suflicient depth to prevent its removal in the event that paint, varnish or other surface finish coatings are subsequently removed by the usual mechanical methods. Obviously, any desired decorative color scheme is possible. For example, instead of a striped effect, the appearance of burnt wood may be created.

The finishing process must be carried out promptly after the removal of the panels from the press, in order to avoid cooling to a temperature too low to melt the resin for the protecting film and to avoid the taking up of too much moisture from the surrounding air. This can be accomplished by carrying each panel directly from the press to a position under a shaking screen and thus causing it quickly to be uniformly covered with powdered resin and then immediately running it between pressure rollers. Handled in this way, it is evident that the cost of providing a panel with the protecting film of resin, over the cost of the resin itself, is not great, so that my improved plywood panels are not much more expensive than ordinary plywood panels.

It will, of course, be evident that any wood panel, whether multiple-ply or not, may be treated to provide it with the continuous protective film of resin, although at a higher cost if it must be heated and dried for that purposealone. The final product, whether the surface-impregnating treatment be given to a panel that must first be heated and dried, or to a panel that comes from the gluing press hot and dry, has a surface inert to weathering, water-resistant to a high degree, and adapted to receive a good paint finish with a minimum amount of painting. Furthermore, the process in both cases eliminates the need of costly solvents for the resin and the fire ha a d that accompanies the use of such-solvents, permits the use of resinous materials not readily mixed with solvents or else generally insoluble in solvents. In both cases the actual completion of the surfacing of the wood is very rapid when compared with the time that is required by varnishes and the like to dry, where the corresponding surface finish is produced by a varnish or paint coat.

-While I have illustrated and described my improved process and product with particularity, I do not desire to be-limited to all of the details thus illustrated and described; but intend to cover all methods and products thereof that come within the definitions constituting the appended claims.

I claim:

1.The method of treating a member of wood which consists in heating and drying it until it has a moisture content of only a very few percent and a high temperature, depositing on the face of said member while the latter is dry and hot a synthetic resin, and rolling the resin into the wood and causing all of it to penetratebelow the plane of said face.

2. The method of treating'a member of wood which consists in heating and drying it until it has a low moisture content and a high temperature, depositing on the face of said member while the latter is dry and hot a thermosetting synthetic resin, and pressing and cooling the resin to cause the latter to penetrate into the wood below the plane of said face.

.3. The method of treating a member of wood which consists in heating and drying it until it has a low moisture content and a temperature of about 250 F. or more, depositing on the face of said member while the. latter is still hot dry,

powdered synthetic resin of a kind that is melted by the heatof said member, and pressing the resin into the hot wood.

4. The method of treating a member of wood which consists in heating and drying it until it has a low moisture content and a temperature of about 250 F. or more, depositing on the face of said member while the latter is still hot a powdered thermosetting synthetic resin of a kind that is melted by the heat of said member, and pressing the resin into the hot wood and simultaneously chilling it.

5. The method of producing and finishing a plywood panel which consists in gluing up a panel by a hot process, employing pieces of wood and glue of such moisture contents and applying heat to such a degree that the glued panel has a low moisturecontent and a high temperature upon leaving the press, and then, while the panel remains dry and hot, depositing on a face thereof a powdered synthetic resin that is melted by the heat of the panel, and applying pressure to squeeze the melted resin into the wood.

6. The method of producing and finishing a plywood panel which consists in gluing up a panel by a hot process, employing pieces of wood and glue of such moisture contents and applying heat to such a degree that the glued panel has a low moisture content and a high temperature upon leaving the press, and then, while; the panel ture, depositing on the face of said member while the latter is dry and hot a material that will not penetrate the wood at ordinary temperatures and melts at said high temperature, and pressing said material against the hotwood.

CHARLES E. ROZEMA. 

